您的客户正在仔细查看其报告，并发现 Search Ads 360 在使用之前生成的基本线性归因模型来跟踪转化，而非其上周设置的以数据为依据的归因模型。 为什么 Search Ads 360 可能会默认使用之前的模型？

Search Ads 360 requires a minimum amount of conversion data to build and maintain a data-driven attribution (DDA) model. If the account's clicks and conversions fall below these data thresholds, Search Ads 360 will default to a rules-based model, such as the basic linear attribution model, because it lacks sufficient data to accurately generate and update the DDA model. The number of keywords in a bid strategy does not directly impact the attribution model's data requirements. While a DDA model does learn over time, its initial creation and ongoing use are contingent on meeting the data thresholds, not just being in a learning phase. Historical data transfer is part of the setup but doesn't prevent the model from defaulting if data requirements aren't met.